Creating a comprehensive security strategy for networks is a multifaceted problem requiring protection techniques at a number of different layers of the network. Physical intrusion at layer 0 of the network—for example the optical fibers that carry the signals in an optical network—can not always be effectively dealt with at higher layers. For example; some encryption techniques are inadequate; sometimes only data is encrypted leaving source and destination addresses exposed. Even traffic level monitoring can be analyzed to reveal important information about real time events. Additionally, jamming or denials of service techniques are harder to stop once an intruder has access to the fiber. Though a large range of possible solutions has been investigated over the past few years, from quantum physics to artificial intelligence processing, no simple, effective mechanism exists today to automatically detect physical fiber intrusion.